Radiology Fellows Research Articles

Supraacetabular Fossa (Pseudodefect of Acetabular Cartilage): Frequency at MR Arthrography and Comparison of Findings at MR Arthrography and Arthroscopy

To evaluate the frequency of the supraacetabular fossa (SAF) (pseudodefect of acetabular cartilage) at magnetic resonance (MR) arthrography of the hip and to compare the MR findings with those from arthroscopy. All patients gave written permission for anonymized use of their medical data for scientific purposes before the imaging examination. The study was submitted to the institutional review board, and the need to obtain additional approval was waived. A medical student, a radiology fellow, and two senior radiologists reviewed 1002 consecutive MR arthrograms for the presence of an accessory bony fossa in the roof of the acetabulum, or SAF. SAF was classified into two types: type 1, which was filled with contrast material on MR arthrograms, and type 2, which was filled with cartilage. The width of the SAF was measured on coronal and sagittal MR images. MR arthrograms showing SAF were evaluated for subchondral reactions. Findings at MR arthrography were compared with those from arthroscopy in four hip joints with SAF type 1 and 13 with SAF type 2. Sixteen of the 1002 hip joints (1.6%; four female and 12 male patients; mean age, 20.1 years) had SAF type 1 (mean width, 5.2 × 4.5 mm). Eighty-nine hip joints (8.9%; 43 female and 46 male patients; mean age, 37.8 years) had SAF type 2 (mean width, 5.1 × 4.7 mm). No subchondral changes were found around the SAF. No cartilage defect was seen at the site of the SAF at arthroscopy. The high frequency of SAF on MR arthrograms (10.5%), the absence of subchondral reaction, and the absence of cartilage defects at arthroscopy indicate that the SAF of the acetabulum likely represents a variant.

FDG PET/CT interobserver agreement in head and neck cancer

Interobserver agreement in measuring positron emission tomography (PET)/computed tomography (CT) parameters is critical for head and neck cancer management. The purpose of this study is to assess the interobserver agreement when measuring the standardized uptake value (SUV) parameters and the diameter of primary head and neck tumors between readers with varied experience in PET/CT. PET/CT images of 47 patients (59.8 ± 10.6 years, range 26-86 years) with head and neck cancer who had a baseline PET/CT at our institution (January 2007-May 2009) were retrieved and independently reviewed by four readers with varying experience reading PET/CT. Novice reader 1 was a preinternship medical student; novice reader 2 was a fourth-year radiology resident; expert reader 1 was a board-certified radiologist with a nuclear radiology fellowship and a junior faculty; and expert reader 2 was a dual radiology and nuclear medicine board-certified radiologist and a senior faculty. Intraclass correlation coefficients (ICCs) were estimated separately across novice and expert readers, between novice 1 and expert 1, and between novice 2 and expert 1 readers. The ICCs (95% confidence interval) for primary tumor diameter, primary tumor SUVmax, and primary tumor SUVmax normalized to liver SUVmean within novices were 0.36 (0.09-0.59) (slight agreement), 0.60 (0.38-0.80) (fair agreement), and 0.91 (0.84-0.94) (almost perfect agreement), respectively. ICCs within experts were 0.84 (0.73-0.90) (almost perfect agreement), 0.91 (0.84-0.94) (almost perfect agreement), and 0.91 (0.84-0.95) (almost perfect agreement), respectively. The ICCs between novice 1 and experts are lower than those between novice 2 and experts for all parameters, and this disparity is greater for anatomic diameter than for fluorodeoxyglucose metabolic parameters. Fluorodeoxyglucose metabolic parameters have higher interobserver agreement than anatomic diameter measurement and are more robust in the setting of varied reading experiences.

Abstract No. 317: The utility of a dedicated interventional radiology fellow website

While many radiology residencies have their own personalized resident websites for keeping track of schedules, gathering helpful documents, tracking conference attendance and making announcements, fellows are often left to hunt for the information they need. IR fellows in particular have a strong need for easy hospital wide access to relevant paperwork and information. Our purpose is to demonstrate the utility of having a dedicated and independent interventional radiology fellowship website to simplify and centralize information necessary for functioning efficiently and productively on the IR service. HTML, Javascript and PHP scripting languages were utilized to set up a secure, password-protected website that contains information necessary for functioning on our institution's service. A number of relevant documents including the basics of how to use the hospital electronic records systems, patient care related information such as consent forms, a method for managing anonymous and secure patient lists, pre-procedure workups, basic IR relevant management algorithms, and hospital phone numbers were compiled into a centralized, easy to remember secure website accessible throughout the hospital. Information on the day-to-day runnings of the fellowship such as fellow and resident rotation schedules, conference schedules, journal clubs, attendance records, and contact numbers were also integrated. An RSS feed from the Journal of Vascular and Interventional Radiology containing abstracts from the most recent articles was also included to give fellows a quick glimpse at new research whenever they log in. A large part of being an interventional radiology fellow or a resident rotating on the interventional radiology service is taking care of patients before and after their procedures. In order to simplify obtaining and keeping track of patient information and having consents and workup forms readily available on the floors, an easy to remember secure website accessible throughout the hospital facilitates this greatly.

The Radiology Fellowship Application and Selection Process in the United States: Experiences and Perceptions from Both Sides

Objective. Our purpose was to investigate radiology fellowship directors' and recent fellows' experiences and perceptions with regard to the fellowship application and selection process and to compare these experiences and perceptions. Materials and Methods. Institutional review board approval was obtained. We conducted an online survey of the memberships of three radiology subspecialty societies between October 2009 and December 2009 to learn about radiologists' views regarding various aspects of radiology fellowships. Results. In the process of selecting fellows, program directors and recent fellows consider performance during the radiology residency and the quality or prestige of the residency program as the most important objective factors, and the personal interview, letters of recommendation, and personality as the most important subjective factors. 25% of the program directors were in the match, and 41% of the recent fellows were in the match. Most (48%) of program directors favored a match, but most (56%) of the recent fellows disfavored participating in a match. Both program directors and recent fellows expressed satisfaction with the fellowship application and selection process. Conclusion. There was no majority support for a fellowship match among program directors and recent fellows and less support among recent fellows. Recent fellows appear more satisfied with the current selection and application process than program directors.

Long bone fracture detection in suspected child abuse: contribution of lateral views

ACR guidelines for routine skeletal survey for child abuse recommend only AP radiographs of the long bones; however, many institutions add lateral radiographs. To evaluate whether adding lateral radiographs for long bones changes the frequency and confidence of fracture detection in skeletal survey radiographs for suspected abuse. We identified 100 children younger than 2years of age who underwent skeletal survey for child abuse; 56 with multiple long bone fractures, 22 with a single fracture and 22 with no fractures. Four radiologists (two pediatric radiologists, one pediatric radiology fellow and one general radiologist) evaluated two randomized series (one series included only frontal, and the other series, frontal and lateral radiographs). Likert scale of 1-5 was used to score for detection of metaphyseal and diaphyseal fractures. For combined readers, significantly more metaphyseal fractures (P = 0.01) were detected with the two-views series of radiographs compared with the frontal-only view; there was no significant difference for diaphyseal fractures. Confidence was also significantly higher for the two-views series. Kappa improved (from 0.32 to 0.48) when the lateral view was added only for the metaphyseal fractures. Adding lateral radiographs resulted in increased detection and confidence levels of metaphyseal fractures.

Enhancing the case log by coding the level of trainee participation in vascular interventional radiology procedures.

The purpose of this article is to describe a new method for coding trainee participation in vascular interventional radiology procedures. From July 2008 through June 2009, all interventional radiology fellows maintained an enhanced case log at our institution; 748 unique cases were logged by procedure type, supervising physician, and level of participation in the case. Level of participation was classified on a 5-point scale that included designations for observation, first assistant, performance of basic techniques, performance of advanced techniques, and primary operation. Descriptive statistics of participation scores were calculated for each quarter and were analyzed by procedure type and by teaching faculty member. As expected, analysis by procedure type showed that average participation scores increased from one quarter to the next in most cases. By the fourth quarter, the modal participation score was 5, indicating primary operation or performance of multiple critical steps. Analysis by teaching faculty member revealed three patterns: those attending physicians facilitating increasing levels of participation in every quarter, those facilitating maximal growth within the first 6 months, and those with irregular trainee participation profiles. Data from a 5-point participation scale add information to the procedure case log that could be used to quantitatively track the technical progress of trainees while providing education quality feedback to both teaching physicians and program directors.

Pediatric radiology fellows’ experience with intussusception reduction

Intussusception reduction allows young children to avoid surgery. However, graduating residents have had relatively little training in intussusception reduction and, for the most part, consider themselves ill-prepared to perform this procedure. The goal of this study was to assess the extent of training in intussusception reduction during one year of a pediatric radiology fellowship and to determine whether graduating fellows consider themselves adequately trained in this technique. Pediatric radiology fellows were surveyed during June 2010 and asked to characterize their fellowship, to indicate the number of intussusception reductions performed (both the total number and those performed with faculty oversight but without active faculty involvement), and to assess the adequacy of their training. There were 31 responses, representing almost 1/3 of current fellows. Pediatric radiology fellows perform on average 6.9 reductions, 3.8 of which are with faculty oversight but without active faculty involvement. Ninety percent consider themselves well-trained in the technique, whereas 10% are uncertain (none consider their training inadequate). Almost all pediatric radiology fellows consider their training in intussusception reduction to be adequate.

Improving Communication of Diagnostic Radiology Findings through Structured Reporting

To compare the content, clarity, and clinical usefulness of conventional (ie, free-form) and structured radiology reports of body computed tomographic (CT) scans, as evaluated by referring physicians, attending radiologists, and radiology fellows at a tertiary care cancer center. The institutional review board approved the study as a quality improvement initiative; no written consent was required. Three radiologists, three radiology fellows, three surgeons, and two medical oncologists evaluated 330 randomly selected conventional and structured radiology reports of body CT scans. For nonradiologists, reports were randomly selected from patients with diagnoses relevant to the physician's area of specialization. Each physician read 15 reports in each format and rated both the content and clarity of each report from 1 (very dissatisfied or very confusing) to 10 (very satisfied or very clear). By using a previously published radiology report grading scale, physicians graded each report's effectiveness in advancing the patient's position on the clinical spectrum. Mixed-effects models were used to test differences between report types. Mean content satisfaction ratings were 7.61 (95% confidence interval [CI]: 7.12, 8.16) for conventional reports and 8.33 (95% CI: 7.82, 8.86) for structured reports, and the difference was significant (P < .0001). Mean clarity satisfaction ratings were 7.45 (95% CI: 6.89, 8.02) for conventional reports and 8.25 (95% CI: 7.68, 8.82) for structured reports, and the difference was significant (P < .0001). Grade ratings did not differ significantly between conventional and structured reports. Referring clinicians and radiologists found that structured reports had better content and greater clarity than conventional reports.

International skeletal society outreach in Colombia

The Colombian ISS outreach program was conducted in collaboration with the Department of Diagnostic Imaging of the University Hospital of San Ignacio at the Pontificia Universidad Javeriana (PUJ) in Bogota and as a part of the XXXV Congress of the Colombian Radiological Association (ACR) in Cartagena from August 3 to 6, 2010. Both meetings were enthusiastically attended with an average of 140 participants per day. Members of the ISS outreach team included Dr. Javier Beltran from Brooklyn, NY, Dr. Diego Jaramillo from Philadelphia, PA, and Jenny T. Bencardino from New York, NY. All lectures were given in Spanish. The program in Bogota was held at the Carlos Galan Auditorium of the PUJ from August 3 to 4, 2010. Bogota is the capital city of Colombia and has a population of over 8 million people. Currently, there are more than 100 higher education institutes and ten medical schools in Bogota, which play a vital role in the life of the city and its economy. In 2007, Bogota was named a World Book Capital City by UNESCO [1]. Bogota is the first Latin American city to receive this recognition, and the second one in the Americas after Montreal. No wonder that many refer to Colombia’s capital as “The Athens of South America” [2]. The attendees to the outreach program in Bogota were radiologists, orthopedic surgeons, technologists, residents, and fellows in radiology and orthopedics. The audience was very engaged, and the use of a digital interactive response system added greatly to their learning experience. The Outreach program in Cartagena was held at the Julio Cesar Turbay Ayala Convention Center, from August 5 to 6. Cartagena is a city of almost 1 million people located on the Colombian Caribbean coast. Its colonial walled city and fortresses have been designated a UNESCO World Heritage Site. Gabriel Garcia Marquez’s novel Love in the Time of Cholera is set in Cartagena. The city is very often used as a gathering place for international and national conventions. The 2010 ACR annual meeting in Cartagena had an attendance of 800 radiologists both local and from other Latin American countries. The musculoskeletal program lasted 2 days. The topics of the Outreach Program in Colombia were both basic and advanced in the areas of general and pediatric musculoskeletal radiology with an average of eight lectures per faculty member. All of the ISS Outreach Program teachers participated as jurors of the Evaluating Committee scoring scientific papers and educational exhibits presented at the ACR meeting in Cartagena. The Colombian outreach program provided us with a unique opportunity to interact academically and share professional experiences with a large body of radiologists from Colombia and other Latin American countries. Some of the information presented in this report was collected informally during our visit. Located in northern South America, Colombia is bordered to the north by the Caribbean Sea between Panama and Venezuela, to the east by Venezuela and J. T. Bencardino (*) Department of Radiology, NYU Hospital for Joint Diseases, 301 East 17th Street, New York, NY 10003, USA e-mail: jenny.bencardino@nyumc.org

Imaging of spondylolisthesis

Dr Guillaume Bierry earned his PhD from the University of Strasbourg, France, in 2008. After completing his residency in Radiology at the University Hospital of Strasbourg and at Cochin University Hospital, Paris in 2007, Dr. G. Bierry was board-certified. He then did his Fellowship in Musculoskeletal and Interventional Radiology at the University Hospital of Strasbourg in 2009. His academic and hospital appointments include Assistant Professor at the School of Medicine, University of Strasbourg and Staff radiologist at the University Hospital of Strasbourg. Dr. Guillaume Bierry is a member of the French Society of Radiology, the European Radiology Society and the Radiological Society of North America.

Abstract No. 327: Simulation 101: How to build a simulation curriculum in an interventional radiology fellowship program

Abstract No. 327: Simulation 101: How to build a simulation curriculum in an interventional radiology fellowship program

Orion: A Web-Based Application Designed to Monitor Resident and Fellow Performance On-Call

Radiology residency and fellowship training provides a unique opportunity to evaluate trainee performance and determine the impact of various educational interventions. We have developed a simple software application (Orion) using open-source tools to facilitate the identification and monitoring of resident and fellow discrepancies in on-call preliminary reports. Over a 6-month period, 19,200 on-call studies were interpreted by 20 radiology residents, and 13,953 on-call studies were interpreted by 25 board-certified radiology fellows representing eight subspecialties. Using standard review macros during faculty interpretation, each of these reports was classified as "agreement", "minor discrepancy", and "major discrepancy" based on the potential to impact patient management or outcome. Major discrepancy rates were used to establish benchmarks for resident and fellow performance by year of training, modality, and subspecialty, and to identify residents and fellows demonstrating a significantly higher major discrepancy rate compared with their classmates. Trends in discrepancies were used to identify subspecialty-specific areas of increased major discrepancy rates in an effort to tailor the didactic and case-based curriculum. A series of missed-case conferences were developed based on trends in discrepancies, and the impact of these conferences is currently being evaluated. Orion is a powerful information technology tool that can be used by residency program directors, fellowship programs directors, residents, and fellows to improve radiology education and training.

Reply regarding Starreveld scoring method and constipation

Sir, We thank Prof. Wiwanitkit for his comments on our article “Starreveld scoring method in diagnosing paediatric constipation”. Regarding the first question we indeed used strict criteria to diagnose children with functional constipation (Iowa criteria) and made an effort to distinguish these children from those who have functional nonretentive faecal incontinence (FNRFI) and functional abdominal pain (FAP), using the at that time valid Rome II criteria [1]. According to the Rome II criteria, constipation in these conditions (FNRFI and FAP) is ruled out and therefore their abdominal radiographs were used as controls [2]. Regarding the second question we indeed used four observers. Although in most reports three raters are used we used four raters to cover the complete range of experience in rating abdominal radiographs (student, radiology fellow, radiologist and paediatric radiologist). We are not aware of statistical hurdles in this respect. Differences in experience do indeed result in different repeated scoring; however in our investigation, to our surprise, the student did best. The student was trained to apply the Starreveld score on two occasions; the other raters used the score on a basis “as described”. Finally, regarding the third question, Prof. Wiwanitkit could be right; however, our groups will become too small to give a statistically sound and definite answer.

Special Issue: Imaging of gastrointestinal and urogenital tracts

This special issue focuses on imaging of the gastrointestinal and urogenital tracts; the papers were initially presented at the European Course of Paediatric Radiology (ECPR) in 2009 in Amsterdam, the Netherlands. The ECPR is an annual course with four revolving topics, i.e. chest/cardiovascular, musculoskeletal, neuroradiology (in collaboration with the European Society of Neuroradiology and the European Society of Magnetic Resonance in Neuropediatrics) and the gastrointestinal/urogenital tract. The aim of this annual course is to enhance knowledge in paediatric radiology; both focussed at fellows in paediatric radiology as well as established radiologists with a special interest in our discipline. It also serves as a meeting point at which collegial and social bonds across borders are formed and enhanced. Paediatric radiology of the gastrointestinal and urogenital tracts has seen a significant change in clinical practice over the last decades. Although as a result of close patient contact, our discipline always has been and hopefully will remain a highly clinically involved field of radiology, changes in diagnostic strategies have changed our daily practice. In many paediatric radiology departments today the fluoroscopy rooms are unoccupied most of the time and barium, in many cases, has been replaced by gadolinium. The purpose of this special issue is to provide an up-to-date overview of imaging of the gastrointestinal and urogenital tracts. Apart from the use of fluoroscopy, which in selected cases is still very valuable as a diagnostic tool, the use of CT and especially MRI is discussed. The use of MRI has taken off and there are promising developments that make the application of this technique an increasingly realistic diagnostic modality in the field of paediatric radiology. In addition to imaging of anatomical structures, MRI can be used to measure function. Using dedicated software (available as freeware) parameters such as renal transit time and differential renal function can be calculated. This makes MRI a one-stop-shop imaging technique for renal diseases. In abdominal imaging the application of diffusion-weighted imaging (DWI) and diffusion-weighted whole-body imaging with background signal suppression (DWIBS) opens new frontiers where anatomical and functional imaging are combined in one modality. Another exciting development is the implementation of interventional radiology. Along with the development of minimally invasive surgery, interventional radiology is gaining ground within paediatrics. The acceptance however, has not reached a level comparable to that in adult medicine, where interventional radiology has a strong position and interventional radiologists are seen as an important asset to any radiological department. In two papers the application of gastrointestinal and urogenital interventional radiology is discussed; it is hoped that these papers will aid further development and implementation of these techniques in paediatric radiology. The combination of close patient contact, the daily pleasure of working with children and their parents and rapid implementation of state-of-the-art imaging modalities makes paediatric radiology a unique subspecialty. It has been shown that the use of advanced/multimodality imaging and intellectual challenges in the USA are among the top reasons for choosing a subspecialty career. I believe that paediatric radiology offers both and it is therefore surprising to see that throughout Europe and the USA there is still a relative shortage of paediatric radiologists. As an editor of this special issue, and on behalf of my co-organisers Mrs. A.M.J.B. Smets and Mrs. E.E. Deurloo, I would like to thank the faculty of the 2009 ECPR for their contribution to the education of a new generation of paediatric radiologists.

Changes in ACGME program requirements for pediatric radiology fellowships

Changes in ACGME program requirements for pediatric radiology fellowships

Compliance with Fleischner Society Guidelines for Management of Small Lung Nodules: A Survey of 834 Radiologists

To determine the familiarity of radiologists with the Fleischner Society guidelines for management of small lung nodules and to assess whether their decisions for nodule management are consistent with these recommendations. Institutional review board exemption was granted for this electronic survey, which was sent to a sample of 7000 radiologists randomly selected from the Radiological Society of North America (RSNA) directory. Three clinical scenarios for nodule management were presented. Information about policies and guidelines for nodule management, awareness of published guidelines, and respondent demographics was obtained. Associations between these parameters and management recommendations were assessed by using a chi(2) test. Respondents were also asked about tube current settings for routine chest computed tomographic examinations and those performed solely for nodule follow-up. Of 834 respondents (response rate, 11.9%), 649 (77.8%) were aware of the Fleischner Society guidelines and 490 (58.8%) worked in practices that employed them or similar guidelines. Management selections were consistent with the Fleischner guidelines in 34.7%-60.8% of responses for the three scenarios. A significantly higher rate of concordance was associated with awareness of the Fleischner guidelines, presence of written policies based on them, a teaching practice setting, practice in a group with at least one member having chest radiology fellowship training, and fewer than 5 years of experience practicing radiology (P < .05 for all associations). The spectrum of tube current settings used was similar between the subgroups of respondents who were aware and those who were unaware of the Fleischner guidelines. Among survey respondents, there was high awareness and adoption of the Fleischner guidelines, but radiologists showed varying degrees of conformance with these recommendations. Future efforts are necessary to bridge the gap between awareness and implementation of these evidence-based guidelines.

A renaissance man

It is rare for a pediatric radiologist to get front-page headlines in The New York Times—especially when he did nothing wrong [1]. Au contraire, H. Theodore (Ted) Harcke is doing pioneering work as chief of forensic radiology at the Armed Forces Institute of Pathology (AFIP) (see commentary “The Case for Postmortem Imaging”). Those who know Ted are not surprised. Ted has had an extraordinary career, graduating from the U.S. Military Academy at West Point with a degree in engineering, serving in active duty in the Army, and then pursuing a master’s degree in education (mathematics) and medical school at Pennsylvania State University College of Medicine. His medical training took him to Children’s Hospital of Philadelphia (internship), Temple University Medical Center (radiology residency), and St. Christopher Hospital for Children (fellowship in pediatric radiology). He was chairman of the Department of Medical Imaging at Alfred I. DuPont Institute in Wilmington, DE, from 1983 to 1995 and held professorships at Temple University School of Medicine, Medical College of Pennsylvania, Jefferson Medical College, and Uniformed Services University of Health Sciences. He served as a visiting scientist at the AFIP. Ted has written extensively with emphasis on pediatric nuclear medicine, pediatric bone disease, and hip US. He is the innovator of dynamic sonography of the hip and taught most of us all we know about it. Ted has found a new passion—learning from the “virtual autopsy” so we can understand mechanisms of disease and devise ways to prevent traumatic injuries. It may seem odd to publish this material in a pediatric radiology journal, but to us, it is a continuation of our role from fetal to newborn to childhood imaging, and to postmortem imaging— all designed to teach, inform, and, we hope, affect outcome. We should all learn from Ted and his inquisitive nature. We congratulate him on a job well done.

Interview: Step Lightly

Dr Sidhu is a partner at Seattle Radiologists and Clinical Assistant Professor at Seattle Children’s Hospital at the University of Washington (WA, USA). Prior to this, she spent 6 years as a full-time member of staff at Seattle Children’s Hospital practicing interventional and pediatric radiology and 1.5 years on staff at Oakland Children’s Hospital (CA, USA). Dr Sidhu completed her Radiology residency and Interventional Radiology fellowship at Stanford Hospital (CA, USA) followed by a Pediatric Radiology fellowship at Seattle Children’s Hospital. Dr Sidhu is Chair of the Interventional Radiology Committee of the Society for Pediatric Radiology and a founding member of the Society for Pediatric Interventional Radiology. She was selected for the Society of Interventional Radiology’s inaugural Leadership Academy class and is the current president of the Society for Pediatric Interventional Radiology.

Interactive dedicated training curriculum improves accuracy in the interpretation of MR imaging of prostate cancer.

To assess the effect of interactive dedicated training on radiology fellows' accuracy in assessing prostate cancer on MRI. Eleven radiology fellows, blinded to clinical and pathological data, independently interpreted preoperative prostate MRI studies, scoring the likelihood of tumour in the peripheral and transition zones and extracapsular extension. Each fellow interpreted 15 studies before dedicated training (to supply baseline interpretation accuracy) and 200 studies (10/week) after attending didactic lectures. Expert radiologists led weekly interactive tutorials comparing fellows' interpretations to pathological tumour maps. To assess interpretation accuracy, receiver operating characteristic (ROC) analysis was conducted, using pathological findings as the reference standard. In identifying peripheral zone tumour, fellows' average area under the ROC curve (AUC) increased from 0.52 to 0.66 (after didactic lectures; p<0.0001) and remained at 0.66 (end of training; p<0.0001); in the transition zone, their average AUC increased from 0.49 to 0.64 (after didactic lectures; p=0.01) and to 0.68 (end of training; p=0.001). In detecting extracapsular extension, their average AUC increased from 0.50 to 0.67 (after didactic lectures; p=0.003) and to 0.81 (end of training; p<0.0001). Interactive dedicated training significantly improved accuracy in tumour localization and especially in detecting extracapsular extension on prostate MRI.

Needle-Based Interventions With the Image-Guided Surgery Toolkit (IGSTK): From Phantoms to Clinical Trials

We present three image-guided navigation systems developed for needle-based interventional radiology procedures, using the open source image-guided surgery toolkit (IGSTK). The clinical procedures we address are vertebroplasty, RF ablation of large lung tumors, and lung biopsy. In vertebroplasty, our system replaces the use of fluoroscopy, reducing radiation exposure to patient and physician. We evaluate this system using a custom phantom and compare the results obtained by a medical student, an interventional radiology fellow, and an attending physician. In RF ablation of large lung tumors, our system provides an automated interventional plan that minimizes damage to healthy tissue and avoids critical structures, in addition to accurate guidance of multiple electrode insertions. We evaluate the system's performance using an animal model. Finally, in the lung biopsy procedure, our system replaces the use of computed tomographic (CT) fluoroscopy, reducing radiation exposure to patient and physician, while at the same time enabling oblique trajectories which are considered challenging under CT fluoroscopy. This system is currently being used in an ongoing clinical trial at Georgetown University Hospital and was used in three cases.